President Donald Trump has announced his intention to ban so-called "bump stock" accessories, which were used to kill 58 people in Las Vegas last year.

Mr Trump made the announcement at the White House during a Medal of Valour award ceremony, saying that he had signed a memorandum instructing the Justice Department to regulate the firearm accessories that can speed up the rate of fire for semi-automatic rifles. The news came just days after 17 people were shot and killed at a Florida school by a teenager using a semi-automatic weapon that was not fitted with the device.

"We can do more to protect our children. We must do more to protect our children," Mr Trump said, claiming school safety has now become the top priority of his administration.

The new announcement comes as pressure is being put on members of Congress and politicians around the country who accept money from the National Rifle Association (NRA), and who have proved instrumental in slowing or stopping gun control legislation that advocates say could have helped to stop events like those in Florida. Students there have been organising marches across the country to protest gun violence, and to champion gun control legislation.

The NRA, following the shooting in Las Vegas, announced that the organisation supports bans on bump stocks, so long as the ban were implemented within the framework of existing laws and regulatory powers. Critics saw that announcement as a strategic ploy to divert attention from stricter gun control proposals.

Mr Trump is scheduled to hold a series of meetings with stakeholders in the gun control debate starting Wednesday, when high school students and teachers from Florida are due to discuss their concerns. He will continue to meet with state and local politicians, as well as law enforcement representatives, White House Press Secretary Sarah Huckabee Sanders said during her televised briefing on Tuesday.

The Bureau of Alcohol, Tobacco, and Firearms and the Department of Justice announced in December that they were reviewing the bump stock issue.

"Sign after sign this week that we've hit a fulcrum point in this debate where politicians are, for the first time, scared on the political consequences of inaction on guns," Mr Murphy wrote on Twitter. "Small, but vital step in the history of our movement."

Ms Huckabee Sanders had indicated, just before Mr Trump's announcement, that the relevant agencies were nearing the completion of their study into bump stock regulations.

"I can tell you that the President supports not having the use of bump stocks," she said. "The president does not support the use of those accessories."

Bump stock accessories essentially convert semi-automatic weapons into automatic weapons, which are banned in the United States. They allow semi-automatic rifles - which fire just a single bullet after each trigger pull - to fire repeatedly without continued trigger pressures.